1. Field of the Invention
The present invention relates to processes and apparatus for recording image signals onto a recording medium, and more particularly, to processes and apparatus dedicated to conservation of space on a recording medium of a security system.
2. Description of the Related Art
In general, a signal obtained by monitoring a volume using a security camera, can optionally be recorded onto a recording medium, and then the recorded images are reproduced to be used as reference material in order to review an abnormal situation, such as, by way of example, the occurrence of a fire within, or an unauthorized entry into, the secured volume during the observation. Earlier efforts in the art included the Electronic Still Camera For Generating Long Time Exposure By Adding Results Multiple Short Time Exposures, U.S. Pat. No. 4,614,966 by Y. Yunoki, et alii; the Motion Detecting Circuit For Digital Video Signal, U.S. Pat. No. 4,851,904 of T. Miyazaki, et alii; the Camera Moving Apparatus, U.S. Pat. No. 5,091,781 of B. An; the Video Movement Detector, U.S. Pat. No. 4,458,266 of T. W. Mahoney; the Motion Detection Apparatus As For An Interlace To Non-Interlace Scan Converter, U.S. Pat. No. 5,027,201 of F. S. Bernard; and the Security Protection System And Method, U.S. Pat. No. 5,144,661 of Robert Shamosh, et alii.
I have found however, that recording media have finite capacity that typically prevents recordation of the entire sequence of events within the secured volume during the period of observation. Efforts have been made to minimize the problem in conventional security systems caused by the limited recording time imposed by the finite capacity of the recording medium, by recording only at predetermined intervals. These efforts can not however, indefinitely enlarge the limited recording time available with contemporary systems. Also, no recording will be available of any abnormal situation that occurs during a time interval when recording was not performed.